Actual Tracheal Oxygen Concentrations with Commonly Used Oxygen Equipment

Influence of Jet Nebulization and Oxygen Delivery on the Fraction of Inspired Oxygen: An Experimental Model

“…The ventilatory settings also influenced FiO 2 in our model in the same sense as previously described by Ooi et al, (11) who reported decreasing FiO 2 values with increasing inspiratory flow rates, indeed, various authors have reported decreasing FiO 2 values with increasing minute ventilation (8,15) and respiratory rate (16) (Fig. 4).…”

“…The increase in FiO 2 with increasing oxygen flow rates through an Ncan has been demonstrated in a mannequin model (11) and in humans. (15,16) The study by Gibson et al (15) focused on the FiO 2 variations, measured by tracheal puncture, during oxygen therapy through an Ncan or Ncath in two healthy subjects. Whatever the breathing pattern, FiO 2 increased moderately from 1 to 5 L/min, but increased to a large extent when high oxygen flow rates were achieved (10 and 15 L/min).…”

“…To our knowledge, only one human study has demonstrated the efficiency of the simultaneous administration NcanϩO 2 Neb. (15) However, both gases administered were oxygen at a flow rate of 15 L/min. Because this is not consistent with current clinical practice and recommendations, we preferred to study and compare the efficiency of O 2 Neb and NcathϩAirNeb or NcanϩAirNeb.…”

Right Versus Left Prong Nasal Cannula Flow Delivery and the Effects of Nasal Cycling on Inspired FIO2in an Adult Anatomic Model

“…This may account for the higher F IO 2 observed in this study when compared with previous studies measuring F IO 2 collected on subjects wearing nasal cannulas. [16][17][18] …”

“…15 Previous literature has demonstrated a large variation of measured F IO 2 when delivering oxygen by nasal cannula using different sampling techniques. [16][17][18] Due to this, Ward 14 stated that measured F IO 2 delivered by nasal cannula is not clinically practical, and the stated F IO 2 listed in textbooks is overstated. Limitations of low-flow nasal cannulas include the entrainment of room air when a patient breathes because the nasal cannula fails to provide enough flow to meet the patient's inspiratory demand, and the…”